Re: [fedora-virt] "YOU WILL LOSE ALL DATA ON THIS DRIVE", but the drive is wrong.

From: Eduardo Habkost <ehabkost redhat com>

To: "Daniel P. Berrange" <berrange redhat com>

Cc: Fedora Virtualization Mailing List <fedora-virt redhat com>

Subject: Re: [fedora-virt] "YOU WILL LOSE ALL DATA ON THIS DRIVE", but the drive is wrong.

Date: Thu, 16 Apr 2009 16:36:33 -0300

On Thu, Apr 16, 2009 at 08:03:38PM +0100, Daniel P. Berrange wrote:
> On Thu, Apr 16, 2009 at 01:56:11PM -0300, Eduardo Habkost wrote:
> > On Thu, Apr 16, 2009 at 05:49:51PM +0100, Mark McLoughlin wrote:
> > > On Wed, 2009-04-15 at 18:28 -0400, Robert P. J. Day wrote:
> > > > from earlier, i'm test installing a f11 beta x86_64 guest on a f11
> > > > beta x86_64 host, and i got to the warning dialog:
> > > >
> > > > Error processing drive sda.
> > > > Maybe it needs to be
> > > > reinitialized. YOU WILL LOSE ALL
> > > > DATA ON THIS DRIVE!
> > > >
> > > > i can see from this BZ report:
> > > >
> > > > https://bugzilla.redhat.com/show_bug.cgi?id=492082
> > > >
> > > > i'm assuming, from what i read there, that this is a normal event and
> > > > that, for a new (blank) disk image, one should do the initialization,
> > > > right?
> > >
> > > Yes. It really sucks that we can't remove this warning for this case -
> > > every single user who creates a virtual machine will see it. And it is a
> > > wholly terrifying dialog.
> >
> > Couldn't virt-install initialize an empty partition table on the disk
> > image before launching the guest? It would probably make many OS
> > installers happier.
>
> No, its not that simple. We can't know what partition table the guest
> OS prefers, nor is it practical for non-raw disk formats. We could
> trivially pass a flag to anaconda on its boot command line to tell it
> to initialize the guest, but anaconda devs rejected this useful idea
> as too complicated to implement. Go figure.
I agree that passing a flag to Anaconda would be even better. But just
creating an empty MS-DOS partition table wouldn't hurt, and would work
for other OSes also. We can't be sure if the guest OS prefers it, but
it's better than a zeroed disk for common use cases. But, yes, the
non-raw disk formats make it more complicated to implement.
--
Eduardo